* {
    padding: 0;
    margin: 0;
    font-family: 微软雅黑;
}
.vertical-around {
    display: flex;
    justify-content: space-around;
    align-items: center;
}
.vertical-space-between {
    display: flex;
    justify-content: space-between;
    align-content: center;
}
.vertical-center {
    display: flex;
    justify-content: center;
    align-items: center;
}
.vertical-start {
    display: flex;
    justify-content: flex-start;
    align-items: center;
}